Evaluations of the structural integrity of a composite is of great interest to various industries including the aerospace industry. While the structural integrity of a test part may be examined using different methods or techniques, one category of techniques assess structural viability based on porosity measurements. Moreover, among the available means for measuring porosity, ultrasonic inspection is widely favored and used for its ability to detect relatively low levels of porosity. However, ultrasonic inspection techniques still come with various drawbacks. In particular, ultrasonic porosity measurements can be time consuming, and require direct access to or contact with the test part. Ultrasonic inspection also requires couplants which not only contaminate certain test parts, but also adds additional costs and delays. Furthermore, ultrasonic signals are susceptible to attenuation from porous layers of structures or materials situated closer to the ultrasonic detector, and are thereby blind, or at least much less sensitive, to structures or materials situated behind or underneath detected porous structures or materials.
Accordingly, the present disclosure is directed at addressing one or more of the deficiencies and disadvantages set forth above. However, it should be appreciated that the solution of any particular problem is not a limitation on the scope of this disclosure or of the attached claims except to the extent express noted.